Squeak Etoys is a "media authoring tool"-- software that you can download to your computer
and then use to create your own media. You can write out your project and share it with others.
Etoys runs on any Mac or Windows machine, as well as on the OLPC XO machine.
It is free.
Find out about Etoys.

Text of this guide (for searching): Halo Tools: An Arrow at the Center of Rotation Shows the Direction of Motion. Right click on the turtle, hold down the shift key, then drag the tiny arrowhead at the center of rotation to a new direction. This turtle's head points at the top of the screen but the direction arrow points to a heading of 45.
Click the green clock to start the script. Try it. Change it. A drawing can be rotated to any heading with its Halo's Rotation handle and its green direction arrow can point in any direction too. Try it.